(1) Field of the Invention
Subject invention is related to a small angle generating apparatus and more particularly to generate small measurable angular deviations of a collimated light beam for purposes of calibrating an autocollimator.
(2) Description of the Prior Art
The angular deflections of light rays have been accomplished in the past by converting large mechanical movements into corresponding small movements of reflecting or refracting surfaces. Such methods are expensive due to the required accuracy and repeatability of the moving parts. Besides, some of the mechanical movements used are nonlinear which render such devices hard to calibrate. Some of the prior art devices have used either spur gears or worm gears, both of which lack the desired accuracy. It is thus desirable to have a small angle generating apparatus which is accurate with repeatable results and is not expensive.